According to the Mayo Clinic, type 2 diabetes is a condition that affects the way a person's body processes glucose. Type 2 diabetes is typically known as "adult onset" because it occurs when the body becomes resistant to the effects of insulin over time. Insulin helps the body metabolize glucose, and when the body is resistant to its effects, or when not enough insulin is produced, hyperglycemia results. Hyperglycemia, or elevated blood sugar levels, can have severe long-term consequences including damage to blood vessels, nerves, and to the eyes. While diet and exercise are used first in type 2 diabetes, most patients ultimately need medication to help control their blood glucose levels.
Biguanides
Biguanides are a class of medications that reduce elevated blood sugar levels by reducing glucose production from the liver. The most common medication in this class is metformin, which is sold as the brand name Glucophage. This medication is the first-line drug of choice for the treatment of type 2 diabetes because it does not cause weight gain. It cannot be used in patients with kidney disease because of the risk for a condition called lactic acidosis in these patients.
Sulfonylureas
Sulfonylureas are a class of antidiabetic drugs that educe elevated blood glucose levels by helping the pancreas to increase insulin secretion. Glimepiride, glipizide and glyburide are examples of this class of medication. These medications can be used by themselves or with metformin for an even greater reduction in blood glucose levels. However, patients on a sulfonylurea need to be monitored for symptoms of low blood sugar because this is can be a side effect of this class of drugs.
Meglitinides
Meglitinides are a class of drugs that also stimulate the pancreas to secrete more insulin. The medications regalinide and nateglinide are examples of this class of drug. They are typically taken three times a day prior to meals and like sulfonylureas, can cause low blood sugars as a side effect.
Thiazolidinediones
Thiazolidinediones are a class of medications that help insulin work better in the body and also help to decrease glucose production by the liver. Rosiglitazone and pioglitazone are examples of this class of medication. According to the American Diabetes Association, these medications are not used in patients with or at risk for congestive heart failure because they appear to increase the risk of heart failure in some patients. Also, there is concern that rosiglitazone may increase the risk of heart attacks.
Alpha-Glucosidase Inhibitors
Alpha-glucosidase inhibitors help to lower blood glucose by inhibiting the breakdown of carbohydrates in the intestine. Acarbose and miglitol are two examples of this class of medication and should be taken while eating a meal. While these medications do not result in weight gain, they can have gastrointestinal side effects such as cramping and diarrhea.
DPP-4 Inhibitors
DPP-4 inhibitors are a newer class of medications that work by preventing the breakdown of a compound called GLP-1 that typically reduces blood glucose levels in the body. By preventing the breakdown of GLP-1, more of this compound is available to naturally reduce blood glucose levels. Sitagliptin and saxagliptin are examples of this class of medication.
Considerations
A lab test called the hemoglobin A1c is typically used to measure how well a person's diabetes is controlled. This test gives an average of the blood glucose measurements for the past three months. Each oral medication alone tends to decrease the hemoglobin A1c by one point, while a combination of two medications can decrease it by two points. In some patients, oral medications will not be able to decrease the blood glucose levels enough and insulin therapy may be needed. There are several different types of insulin therapy that work by directly replacing insulin to help to lower blood sugar levels. Insulin must be injected to work properly.
